The invention relates to a method for functionalising a surface of a solid substrate with at least one acrylic acid polymer layer, said method comprising the steps of: i) placing said surface in contact with a solution consisting of at least one acrylic acid homopolymer, a solvent and, optionally, metal salts; ii) removing the solvent from the solution in contact with said surface; and iii) binding the polymer to said surface by thermal treatment.